'86 1.3c - oil light and buzzer...?

[Geeman]

Now my A8 has gone, I've got bags of space for the new Mk2...! So I went to pick it up from Mum & Dads today... about 18 miles away. It had been sat there out the way since I picked it up from Ipswich about 3 months ago!

I made it home no problem, but about 3/4 of the way (about 12 miles) the oil pressure light (and buzzer - scared the crap out of me as wasn't expecting it!) came on at low revs. Drop down a gear and build the revs up and it's fine. It happens when you slow down and the revs drop.

I checked the oil before I left, and it was over full with nice clean oil in it. It's still the same now.

There's a tiny bit of mayo on the oil filler cap, but only a small amount and I put that down to the condensation building up as it's been sat outside for so long. The interior of the car is full of it too (condensation)... so I don't think the headgasket has gone. It did run a little over half way on the temp guage all the time, but never went any further. I took the cap off the coolant resevoir when I got home and the coolant was still where I'd topped it up to and there was no real heavy pressure built up when I took it off.

So... oil pump failure do you think, or is it not as bad as that? Do I keep running it or get it sorted ASAP? Someone said it could be that the return spring is weak and all that might be needed is a replacement (stronger) spring.

What are your thoughts?

Cheers,

Giles

[danny_p]

it chould be an oil pump issue ( worn pump or knackerd relieif valve) or very wrong grade oil.

but every engine ive had with those symptoms has chewed a shell

[Geeman]

Worth dumping the oil (even though it is brand new) and getting the correct grade in there...? It's something the previous owner did, so I'm unsure as to what was put in there...

[rubjonny]

when you say low revs, how low are we talking?

[Geeman]

When you slow down and it goes below say, about 2500, then it'll sound and the warning light will flash. Change down a gear and build the revs up again and it goes off again.

[danny_p]

ummm   possoblity that chould be pressure switch.   

[Geeman]

Only seemed to do it when it was warmed up (after 12 or so miles)...

So I'll order the new oil pressure senders and replace those first I think.

[rubjonny]

the buzzer is only supposed to kick in above around 2k rpm, since you say it kicks in around 2.3k rpm this suggests that you may have a low pressure condition!  Thing is do you have a rev counter, cos if not it'll be hard to tell what revs you're at when its buzzing 

[Geeman]

 :embarassed:

Completely forgot about that! In this car I don't have one (all my other ones do!) - I was just guesstimating.

So, given the glaringly obvious mistake I made, let's start at the beginning...

When the revs drop while driving, the buzzer / light comes on. Increase the revs by either accelerating, or changing down a gear and the light / buzzer goes off. While sat at idle, no buzzer or light. Travelling at 40/50/60 in 4th, no buzzer or light.

Obviously, I don't to damage the engine by driving it with low oil pressure.

Over filling the oil can cause HIGH oil pressure, right? It's over full at the moment (by quite a way) when I checked it.

[rubjonny]

ok, id say the pressure system is probably ok, but without a rev counter its hard to know for sure.  Check the wiring to the  white pressure sensor with a yellow wire, pop the boot off and pull it back down the wire a bit make sure its in good condition, and make sure it isnt pissing oil out of it.  May as well check the low pressure sensor as well, but that will never trigger the buzzer at any point.  Make sure the wires are the right way round though, yellow -> white sensor, blue -> black/blue/brown sensor.

If that all checks out then I'd get another white sensor on there see if that sorts it.  If not, you may really have low oil pressure!  On a 1.3 both sensors are on the back of the head, worn cam caps can cause a low pressure condition here.

1st thing really though is to sort out the oil level, if it was me I'd dump the oil out and put a fresh lot in with a shiny new filter!